Emory University participated in a major international study, published Sept. 16 in the New England Journal of Medicine, showing that brain shunt surgery significantly improves walking and balance in older adults with idiopathic normal pressure hydrocephalus (iNPH). This common but often overlooked and treatable buildup of cerebrospinal fluid in the brain causes memory problems, walking difficulty and urinary incontinence in seniors.
The Placebo-Controlled Effectiveness in iNPH Shunting (PENS) Trial is the first large, randomized study to confirm the benefits of shunting surgery for iNPH. Researchers found that patients who received a working brain shunt walked faster, had better balance and were less likely to fall, results that could change the standard of care for this treatable condition.
The multicenter study, funded by the National Institutes of Health, enrolled 99 patients at 17 sites across the U.S., Canada and Sweden. All participants had surgery to implant a programmable brain shunt — a small device that helps drain excess cerebrospinal fluid (CSF) from the brain. In half the participants, the shunt was turned on immediately. In the other half, it was initially set to a placebo setting that prevented fluid drainage. Neither patients nor their doctors knew which group they were in.
After three months, patients with the active shunt showed significantly faster walking speeds, improved balance and fewer falls compared with those in the placebo group.
“This study settles a decades-long debate and gives us the highest level of evidence that shunting works for iNPH,” says Emory Healthcare neurosurgeon Daniel L. Barrow, MD, the Pamela R. Rollins Chairman and Professor of Neurosurgery at Emory University School of Medicine and a study co-author. “It’s especially meaningful for older adults, who often lose independence because of mobility issues and falls. These results show that early diagnosis and treatment can dramatically improve quality of life.”
The study was a collaboration between neurosurgeons and neurologists, an interdisciplinary approach that mirrors how iNPH is best identified and managed in real-world clinical settings, according to Barrow.
The findings showed, on average, walking speed in the open-shunt group improved by 0.23 meters per second, more than double the threshold considered meaningful for older adults. In the placebo group, walking speed remained virtually unchanged. In addition, 80% of patients in the active group experienced meaningful improvement, compared with just 24% of those in the placebo group.
Falls were also significantly reduced: just 25% of the active group reported a fall, compared with 46% in the placebo group.
Despite its treatability, iNPH is frequently missed or mistaken for normal aging. Experts estimate that only about 20% of eligible patients are ever referred for evaluation.
“There’s a real opportunity here to change how we identify and treat iNPH,” Barrow says. “Too often, these patients are told nothing can be done. This study shows that with the right diagnosis and intervention, we can give them a much better outcome.”
Researchers report that iNPH affects up to 1.5% of people in their late 60s and as many as 1 in 13 over age 86. Symptoms include difficulty walking, memory issues and loss of bladder control, a combination that can easily be mistaken for other age-related conditions. Diagnosis typically involves brain imaging and tests to evaluate how patients respond to temporary fluid drainage. Currently, the only effective treatment is implanting a shunt to continuously drain excess CSF.
Looking ahead, the PENS trial will continue to follow participants for 12 months to measure long-term outcomes, including cognition, daily functioning and quality of life. Early findings already suggest gains beyond walking.
Researchers are also working to develop noninvasive diagnostic tools to make it easier to detect iNPH earlier and connect patients to appropriate treatment.
The PENS trial was led by Johns Hopkins University School of Medicine and the Adult Hydrocephalus Clinical Research Network. Additional participating institutions included the University of Washington, University of Calgary, Mayo Clinic, Oregon Health & Science University, University of Miami, University of South Florida, University of California-Davis, University of Utah and others.
For more information on the PENS trial, visit clinicaltrials.gov.